Active input/output expander of a memory sub-system

ABSTRACT

A read command to read a target memory die of a memory sub-system is received from a host system via a host-side interface of an active input/output (I/O) expander. The active I/O expander identifies a page address corresponding to the target memory die and decodes the read command to send to a memory stack associated with the page address corresponding to the target memory die. Read data is received via a memory-side interface of the active I/O expander from the memory stack including the target memory die. A signal conditioning operation is performed on the read data to generate conditioned read data. The active I/O expander sends, via the host-side interface, the conditioned read data to the host system.

TECHNICAL FIELD

Embodiments of the disclosure relate generally to memory sub-systems,and more specifically, relate to an active input/output expander of amemory sub-system.

BACKGROUND

A memory sub-system can be a storage system, such as a solid-state drive(SSD), or a hard disk drive (HDD). A memory sub-system can be a memorymodule, such as a dual in-line memory module (DIMM), a small outlineDIMM (SO-DIMM), or a non-volatile dual in-line memory module (NVDIMM). Amemory sub-system can include one or more memory components that storedata. The memory components can be, for example, non-volatile memorycomponents and volatile memory components. In general, a host system canutilize a memory sub-system to store data at the memory components andto retrieve data from the memory components.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will be understood more fully from the detaileddescription given below and from the accompanying drawings of variousembodiments of the disclosure.

FIG. 1 illustrates an example computing environment that includes amemory sub-system in accordance with some embodiments of the presentdisclosure.

FIG. 2 illustrates an example active input/output (I/O) expanderassociated with a memory sub-system in accordance with some embodimentsof the present disclosure.

FIG. 3 a flow diagram of an example method associated with configuringand calibrating an active I/O expander of a memory sub-system inaccordance with some embodiments of the present disclosure.

FIG. 4 is a flow diagram of example method of an active I/O expanderprocessing a read command from a host system in accordance with someembodiments of the present disclosure.

FIG. 5 is a flow diagram of example method of an active I/O expanderprocessing a read command from a host system in accordance with someembodiments of the present disclosure.

FIG. 6 illustrates an example of multiple active I/O expanders eachassociated with multiple memory stacks in accordance with someembodiments of the present disclosure.

FIG. 7 is a block diagram of an example computer system in whichembodiments of the present disclosure may operate.

DETAILED DESCRIPTION

Aspects of the present disclosure are directed to an active input/output(TO) expander of a memory sub-system. An example of a memory sub-systemis a storage device that is coupled to a central processing unit (CPU)via a peripheral interconnect (e.g., an input/output bus, a storage areanetwork). Examples of storage devices include a solid-state drive (SSD),a flash drive, a universal serial bus (USB) flash drive, and a hard diskdrive (HDD). Another example of a memory sub-system is a memory modulethat is coupled to the CPU via a memory bus. Examples of memory modulesinclude a dual in-line memory module (DIMM), a small outline DIMM(SO-DIMM), a non-volatile dual in-line memory module (NVDIMM), etc. Insome embodiments, the memory sub-system can be a hybrid memory/storagesub-system. In general, a host system can utilize a memory sub-systemthat includes one or more memory components. The host system can providedata to be stored at the memory sub-system and can request data to beretrieved from the memory sub-system.

The memory sub-system can include an active IO expander to processcommands (e.g., read, write, read status, get feature, etc.) from a hostsystem corresponding to data stored in a high capacity storage areaincluding multiple memory stacks each having multiple memory die. Theactive IO expander includes an interface to the host system (e.g., ahost-side interface) that is compliant with Open NAND Flash Interface(ONFI) specifications (herein referred to as an “ONFI-compliantinterface” or “ONFI interface”) to send and receive commands inaccordance with the ONFI protocol. The active IO expander furtherincludes an ONFI-compliant interface to the high capacity storage areaincluding the multiple memory stacks (i.e., a memory-side interface).The active IO expander decodes ONFI commands processed via the host-sideinterface and the memory-side interface to program or write data to thememory stacks. The active I/O expander operates as a switch (e.g., a 1×2or 1×4 switch) to select from multiple memory channels to performaddressing functions and communicate with the multiple memory stacks ofthe high capacity storage area in view of the read and write commandsreceived from the host system.

Conventional memory sub-systems include storage areas that have alimited number of dies per each memory channel. Accordingly,conventional interfaces between a controller of the memory sub-systemand the low capacity storage area are configured to support a lowermedia throughput in order to process commands corresponding to thelimited number of dies associated with each memory channel. However,these configurations do not allow for additional memory die to besupported at sufficiently high data transmission rates. As such, asmemory sub-system sizes expand with additional memory die, conventionalinterfaces are not able to support the increased number of memory dieper transmission channel.

Aspects of the present disclosure address the above and otherdeficiencies by including an ONFI-compliant active I/O expander in amemory sub-system to enable an increased number of memory die (e.g.,higher capacity) that can be supported by a controller channel, therebyenabling increased media throughput (e.g., greater than 1200 MT/s). TheONFI-compliant active IO expander can decode ONFI-protocol commandsrelating to writing data to the memory die and reading data from thememory die. The ONFI-compliant active IO expander can perform signalconditioning operations (e.g., buffering, re-timing, re-driving) onsignals sent by the host-side controller to and from the memory die.

Advantages of the present disclosure include, but are not limited to,improved host-side and memory-side interfaces configured to supportONFI-compliant drive strength tuning, on-die termination (ODT), andcalibrating (e.g., ZQ calibration). Furthermore, the ONFI-compliantactive I/O expander enables a host system to connect to a larger numberof memory dies at higher speeds and optimizes power and performancebehavior of the memory sub-system.

FIG. 1 illustrates an example computing environment 100 that includes amemory sub-system 110 in accordance with some embodiments of the presentdisclosure. The memory sub-system 110 can include media, such as memorycomponents 112A to 112N. The memory components 112A to 112N can bevolatile memory components, non-volatile memory components, or acombination of such. In some embodiments, the memory sub-system is astorage system. An example of a storage system is a SSD. In someembodiments, the memory sub-system 110 is a hybrid memory/storagesub-system. In general, the computing environment 100 can include a hostsystem 120 that uses the memory sub-system 110. For example, the hostsystem 120 can write data to the memory sub-system 110 and read datafrom the memory sub-system 110.

The host system 120 can be a computing device such as a desktopcomputer, laptop computer, network server, mobile device, or suchcomputing device that includes a memory and a processing device. Thehost system 120 can include or be coupled to the memory sub-system 110so that the host system 120 can read data from or write data to thememory sub-system 110. The host system 120 can be coupled to the memorysub-system 110 via a physical host interface. As used herein, “coupledto” generally refers to a connection between components, which can be anindirect communicative connection or direct communicative connection(e.g., without intervening components), whether wired or wireless,including connections such as electrical, optical, magnetic, etc.Examples of a physical host interface include, but are not limited to, aserial advanced technology attachment (SATA) interface, a peripheralcomponent interconnect express (PCIe) interface, universal serial bus(USB) interface, Fibre Channel, Serial Attached SCSI (SAS), etc. Thephysical host interface can be used to transmit data between the hostsystem 120 and the memory sub-system 110. The host system 120 canfurther utilize an NVM Express (NVMe) interface to access the memorycomponents 112A to 112N when the memory sub-system 110 is coupled withthe host system 120 by the PCIe interface. The physical host interfacecan provide an interface for passing control, address, data, and othersignals between the memory sub-system 110 and the host system 120.

The memory components 112A to 112N can include any combination of thedifferent types of non-volatile memory components and/or volatile memorycomponents. An example of non-volatile memory components includes anegative-and (NAND) type flash memory. Each of the memory components112A to 112N can include one or more arrays of memory cells such assingle level cells (SLCs) or multi-level cells (MLCs) (e.g., triplelevel cells (TLCs) or quad-level cells (QLCs)). In some embodiments, aparticular memory component can include both an SLC portion and a MLCportion of memory cells. Each of the memory cells can store one or morebits of data (e.g., data blocks) used by the host system 120. Althoughnon-volatile memory components such as NAND type flash memory aredescribed, the memory components 112A to 112N can be based on any othertype of memory such as a volatile memory. In some embodiments, thememory components 112A to 112N can be, but are not limited to, randomaccess memory (RAM), read-only memory (ROM), dynamic random accessmemory (DRAM), synchronous dynamic random access memory (SDRAM), phasechange memory (PCM), magneto random access memory (MRAM), negative-or(NOR) flash memory, electrically erasable programmable read-only memory(EEPROM), and a cross-point array of non-volatile memory cells. Across-point array of non-volatile memory can perform bit storage basedon a change of bulk resistance, in conjunction with a stackablecross-gridded data access array. Additionally, in contrast to manyflash-based memories, cross-point non-volatile memory can perform awrite in-place operation, where a non-volatile memory cell can beprogrammed without the non-volatile memory cell being previously erased.Furthermore, the memory cells of the memory components 112A to 112N canbe grouped as memory pages or data blocks that can refer to a unit ofthe memory component used to store data.

The memory system controller 115 (hereinafter referred to as“controller”) can communicate with the memory components 112A to 112N toperform operations such as reading data, writing data, or erasing dataat the memory components 112A to 112N and other such operations. Thecontroller 115 can include hardware such as one or more integratedcircuits and/or discrete components, a buffer memory, or a combinationthereof. The controller 115 can be a microcontroller, special purposelogic circuitry (e.g., a field programmable gate array (FPGA), anapplication specific integrated circuit (ASIC), etc.), or other suitableprocessor. The controller 115 can include a processor (processingdevice) 117 configured to execute instructions stored in local memory119. In the illustrated example, the local memory 119 of the controller115 includes an embedded memory configured to store instructions forperforming various processes, operations, logic flows, and routines thatcontrol operation of the memory sub-system 110, including handlingcommunications between the memory sub-system 110 and the host system120. In some embodiments, the local memory 119 can include memoryregisters storing memory pointers, fetched data, etc. The local memory119 can also include read-only memory (ROM) for storing micro-code.While the example memory sub-system 110 in FIG. 1 has been illustratedas including the controller 115, in another embodiment of the presentdisclosure, a memory sub-system 110 may not include a controller 115,and may instead rely upon external control (e.g., provided by anexternal host, or by a processor or controller separate from the memorysub-system).

In general, the controller 115 can receive commands or operations fromthe host system 120 and can convert the commands or operations intoinstructions or appropriate commands to achieve the desired access tothe memory components 112A to 112N. The controller 115 can beresponsible for other operations such as wear leveling operations,garbage collection operations, error detection and error-correcting code(ECC) operations, encryption operations, caching operations, and addresstranslations between a logical block address and a physical blockaddress that are associated with the memory components 112A to 112N. Thecontroller 115 can further include host interface circuitry tocommunicate with the host system 120 via the physical host interface.The host interface circuitry can convert the commands received from thehost system into command instructions to access the memory components112A to 112N as well as convert responses associated with the memorycomponents 112A to 112N into information for the host system 120.

The memory sub-system 110 can also include additional circuitry orcomponents that are not illustrated. In some embodiments, the memorysub-system 110 can include a cache or buffer (e.g., DRAM) and addresscircuitry (e.g., a row decoder and a column decoder) that can receive anaddress from the controller 115 and decode the address to access thememory components 112A to 112N.

The memory sub-system 110 includes an ONFI-compliant active I/O expander113 (also referred to as an ONFI-compliant active I/O expander) toprocess commands (e.g., read and write commands) from a host systemrelating to data stored in a high capacity storage area includingmultiple memory stacks having multiple memory die. The ONFI-compliantactive I/O expander 113 includes a first host-side interfacecommunicatively coupled to a host-side controller (also referred to as ahost-side interface) that is compliant with ONFI specifications (hereinreferred to as an “ONFI-compliant”) to send and receive commands inaccordance with the ONFI protocol. In an embodiment, the host-sideinterface can operate at a data transmission rate of betweenapproximately 800 MT/s and approximately 2400 MT/s. The ONFI-compliantactive I/O expander 113 also includes an interface to a high capacitystorage area including multiple memory stacks, where each memory stackcan include multiple memory die (also referred to as the “memory-sideinterface”). In an embodiment, the memory-side interface of theONFI-compliant active I/O expander 113 is configured to operate as ademultiplexer or switch between multiple different memory stacks (e.g.,a 1×2 switch, a 1×4 switch) operating at data transmission rates ofbetween approximately 800 MT/s-2400 MT/s (e.g., depending on a dataloading level and printed circuit board (PCB) trace length)

The active IO expander decodes ONFI commands processed via the host-sideinterface and the memory-side interface to program or write data to thememory stacks. The active I/O expander operates as a switch (e.g., a 1×2or 1×4 switch) to select from multiple memory channels to communicatewith the multiple memory stacks of the high capacity storage area inview of the read and write commands received from the host system. In anembodiment, the memory sub-system 110 includes multiple ONFI-compliantactive I/O expanders 113, where each of the multiple ONFI-compliantactive I/O expanders 113 supports one or more sets of memory components(e.g., memory stacks including multiple memory die) in a 2×2 mode.

In an embodiment, the ONFI-compliant active I/O expander 113 provides acommunication pathway between with the memory component 112A-112N (e.g.,memory die) and the host system 120. In an embodiment, theONFI-compliant active I/O expander 113 presents as the host system 120(or controller 115 of the host system 120) at the memory-side interface.In an embodiment, the ONFI-compliant active I/O expander 113 can have avolume address configuration to process commands from the host system120 and uses volume select commands to select the memory component112A-112N that is the subject of the command (e.g., a read or writecommand). In another embodiment, the ONFI-compliant active I/O expander113 includes a chip enable (CE) decoder to process commands from thehost system 120 and uses CE decoding to select the memory component112A-112N that is the subject of the command.

Advantageously, the ONFI-compliant active I/O expander 113 performs oneor more signal conditioning operations (e.g., buffering, retiming,redriving, etc.) on the signals and corresponding data communicatedbetween the host system 130 and the memory components 112A-112N. TheONFI-compliant active I/O expander 113 operates at ONFI-level speeds andenable parameter tuning (e.g., power management, drive strength (DS),on-die termination (ODT), calibration) to operate for multiple differentmemory configurations at increased speeds (e.g., in a range of 800 MT/sand 2400 MT/s), such as, for example an average operating speed ofapproximately 1200 MT/s. In an embodiment, this enable theONFI-compliant active I/O expander 113 to deliver performance atoptimized power levels.

FIG. 2 illustrates an example ONFI-compliant active I/O expander 213communicatively coupled to a controller 215 of a host system 220 andmultiple memory components (e.g., multiple memory stacks 280A-280D eachhaving sets of multiple memory die (281A-281D). In an embodiment, eachmemory stack (e.g., memory stack 280A) includes a die loading level ofmultiple memory die 281 (e.g., memory die 281A), such as four, eight,sixteen, thirty-two, or sixty-four memory dies per each memory stack andcorresponding ONFI channel (e.g., ONFI channel 290A). The ONFI-compliantactive I/O expander 213 manages signals between the host system 220(e.g., via controller 215) and the memory stacks 280A-280D to executevarious commands (e.g., read and write commands). As shown in FIG. 2,the ONFI-compliant active I/O expander 213 includes a host-side ONFIinterface 260 to communicate with the controller 215 of the host system220 via an ONFI channel 218 (e.g., a channel compliant with the ONFIprotocol and specifications). In an example, the host-side ONFIinterface 260 (e.g., an ONFI4 NV-DDR3 interface) is configured toprocess data at a rate in an approximate range of at least 800 MT/s to1600 MT/s. FIG. 2 illustrates an example 1×4 ONFI-compliant active I/Oexpander 213, where the ONFI-compliant active I/O expander 213communicates with four different memory stacks 280A-280D via respectiveONFI channels 290A-290D.

As shown in FIG. 2, the ONFI-compliant active I/O expander 213 includesa memory-side ONFI interface 270 to communicate with the multiple memorystacks 280A-280D and corresponding memory die 281A-281D via a respectiveONFI channel 290A-290D. In an embodiment, the memory-side ONFI interface270 is an 8-bit data/strobe interface. In an example, the memory-sideONFI interface 260 (e.g., an ONFI4 NV-DDR3 interface) is configured toprocess data at a rate in an approximate range of at least 800 MT/s to1600 MT/s.

The ONFI-compliant active I/O expander 213 also includes a calibrationmodule 230, a signal conditioning module 240, and an ONFI command decodemodule 250 to perform various operations and functions relating to theprocessing of signals between the controller 215 of the host system 220and the memory stacks 280A-280D. In an embodiment, the calibrationmodule 230 configures or tunes one or more parameters of the host-sideONFI interface 260 and the memory-side ONFI interface 270. For example,the calibration module 230 can tune drive strength (DS) and on-dietermination (ODT) settings for the host-side ONFI interface 260 and thememory-side ONFI interface 270. In an embodiment, the calibration module230 can initiate a calibration process to change one or more values ofthe memory-side ONFI interface 270 to enable ONFI-compliantcommunications (e.g., a ZQ calibration process). In an embodiment, thecalibration process can be initiated via the ONFI channel 290A-290Dcorresponding to the memory stack 280A-280D addressed in a read or writecommand to tune parameters in view of the target memory die. In anembodiment including multiple ONFI-compliant active I/O expanders (e.g.,as shown in FIG. 6), in response to a command identifying a memory dieof interest (e.g., a memory die that is subject to the command, alsoreferred to as a “target memory die”), the calibration module 230selects the ONFI-compliant active I/O expander associated with thecorresponding memory stack 280A-280D including the target memory die. Inan embodiment, the calibration module 230 is a component of eachONFI-compliant active I/O expander 213. For example, when there aremultiple ONFI-compliant active I/O expander 213 each with a calibrationmodule 230, the process can be initiated in a broadcast fashion, via ahost-side ONFI channel command, wherein each calibration module 230operates on its respective memory side interface. In an embodiment,there are no communications or coordination between the multipleONFI-compliant active I/O expanders 213.

In an embodiment, the host-side ONFI interface 260 and the memory-sideONFI interface 270 settings (e.g., the DS and ODT settings) can be setto match a parasitic load on the traces and the interfaces of the activeI/O expander.

The ONFI command decode module 250 receives, inspects, decodes andpasses through a read command received from the host system 220 to atarget memory die (e.g., the memory die that is the subject of the readcommand). In an embodiment, the ONFI command decode module 250 providesmemory address information (e.g., memory page address information)associated with the current command (e.g., a destination page addressfor a write command or a page address to read the data for a readcommand).

In an embodiment, the signal conditioning module 240 conditions thesignals transmitted between the host system 220 and the memory stacks280A-280D. In an embodiment, signals received from both the host-sideONFI interface 260 and the memory-side ONFI interface 270 areconditioned (or re-conditioned) in accordance with the ONFIspecifications for transmission via the ONFI interfaces 260, 270 andONFI channels 218, 290A-290D. For example, the signal conditioningmodule 240 can buffer, retime, and re-drive the data to the controller215 of the host system 220 and the memory stacks 280A-280D.

FIG. 3 is a flow diagram of an example method 300 to performconfiguration of parameters and calibration of an ONFI-compliant activeI/O expander of a memory sub-system in accordance with some embodimentsof the present disclosure. The method 300 can be performed by processinglogic that can include hardware (e.g., processing device, circuitry,dedicated logic, programmable logic, microcode, hardware of a device,integrated circuit, etc.), software (e.g., instructions run or executedon a processing device), or a combination thereof. In some embodiments,the method 300 is performed by the ONFI-compliant active I/O expander113 of FIG. 1. Although shown in a particular sequence or order, unlessotherwise specified, the order of the processes can be modified. Thus,the illustrated embodiments should be understood only as examples, andthe illustrated processes can be performed in a different order, andsome processes can be performed in parallel. Additionally, one or moreprocesses can be omitted in various embodiments. Thus, not all processesare required in every embodiment. Other process flows are possible.

At operation 310, the processing device selects, in response to acommand from a host system, an active I/O expander associated with atarget memory die of a memory sub-system. In an embodiment, the targetmemory die is identified as a memory die of interest that is the subjectof a command (e.g., a read command, a write command, etc.) from a hostsystem. In an embodiment, the active I/O expander is selected frommultiple active I/O expanders included within the memory sub-system,where each active I/O expander is connected to multiple memory stacks(e.g., multiple NAND packages), and where each of the multiple memorystacks includes multiple memory dies. An example of a memory sub-systemincluding multiple active I/O expanders is shown in FIG. 6.

In operation 320, the processing device configures a value setting(e.g., a register setting) associated with one or more parameters of atleast one of a host-side ONFI interface and a memory-side ONFI interfaceof the active I/O expander to enable ONFI-compliant communicationsbetween the host system and the target memory die. In an embodiment, theone or more parameters can include a drive strength parameter and on-dietermination (ODT) parameter. In an embodiment, resistor values can beselected to provide optimal slew rate and impedance matching to achievethe desired performance for the loading, without dissipating excesspower. In an embodiment, this behavior can change from system to system,such that the tuning of these settings in firmware provides valuablecontrol functionality. For example, the host-side interface can beconfigured to have a value setting of 37.5 Ohms or 50 Ohms for the drivestrength parameter. In another example, the value setting of the ODTparameter for the memory-side interface can be 50 Ohms, 75 Ohms, 150Ohms, etc.

In an embodiment, configuring the value setting of the one or moreparameters enables operation of the ONFI-compliant active I/O expanderin different memory configurations (e.g., different SSD configurationincluding memory die having single level cells (SLCs), multi-level cells(MLCs), triple level cells (TLCs) or quad-level cells (QLCs)). In anembodiment, configuring the one or more parameters allows theONFI-compliant active I/O expander to be used with different printedcircuit board (PCB) types and memory die loading levels (e.g., thenumber of memory die per channel or memory stack).

In operation 330, the processing device initiates a calibration commandto tune the one or more parameters of at least one of a host-sideinterface or a memory-side interface. In an embodiment, the calibrationcommand is a ZQ calibration command. In an embodiment, the calibrationprocedure can track drift in the drive strength resistor values due toprocess, voltage or temperature variations. In an embodiment,incorporation of the calibration process in an ONFI-compliant active I/Oexpander allows for more accurate performance tracking. In anembodiment, the ZQ calibration (ZQCAL) command can manageprocess-voltage-temperature (PVT) variations in the one or moreparameters (e.g., the drive strength and ODT values).

In an embodiment, operations 320 and 330 can be performed in parallel.In an embodiment, the value settings for the various parameters (e.g.,DS, ODT, DS, ZQCAL) can be configured with an ONFI-compliant set field(SETF) feature with a dedicated address space that is not used by thememory stacks of the sub-system (e.g. the ONFI-compliant active I/Oexpander can decode the dedicated address and not forward any SETFcommands in the address space to the memory stacks).

FIG. 4 is a flow diagram of an example method 400 for an ONFI-compliantactive I/O expander of a memory-subsystem to manage a read commandprovided by a host system in accordance with some embodiments of thepresent disclosure. The method 400 can be performed by processing logicthat can include hardware (e.g., processing device, circuitry, dedicatedlogic, programmable logic, microcode, hardware of a device, integratedcircuit, etc.), software (e.g., instructions run or executed on aprocessing device), or a combination thereof. In some embodiments, themethod 400 is performed by the ONFI-compliant active I/O expander 113 ofFIG. 1. Although shown in a particular sequence or order, unlessotherwise specified, the order of the processes can be modified. Thus,the illustrated embodiments should be understood only as examples, andthe illustrated processes can be performed in a different order, andsome processes can be performed in parallel. Additionally, one or moreprocesses can be omitted in various embodiments. Thus, not all processesare required in every embodiment. Other process flows are possible.

At operation 410, the processing device receives, from a host system viaa host-side interface of an active I/O expander, a read command to readdata of a target memory die of a memory sub-system. In an embodiment,the read command is transmitted via an ONFI channel connecting thehost-side interface with a controller of the host system. In an example,the ONFI channel and host-side interface operate in accordance with theONFI protocol at a rate between 800 MT/s and 1600 MT/s.

In operation 420, the processing device identifies a page addresscorresponding to the target memory die. In an embodiment, the pageaddress can be determined by the flash translation layer (FTL) on thehost-side controller. That in turn communicates with the appropriateONFI channels flash controller which then dispatches the physical memorydie page address to the correct ONFI channel. In an embodiment, theactive I/O expander determines which of the multiple connected memorystacks includes the target memory die and identifies the correspondingpage address.

In operation 430, the processing device decodes the read command to sendto a memory stack associated with the page address corresponding to thetarget memory die. In an embodiment, an ONFI command decode module ofthe active I/O expander (e.g., the ONFI Command Decode Module 250 ofFIG. 2) receives the read command from the host-side ONFI-compliantinterface (e.g., host-side ONFI interface 260 of FIG. 2), inspects theread command, and decodes the read command. In an embodiment, the readcommand format can be specified in the ONFI specifications (e.g., aMulti-Plane Read command can consists of two command cycles 00h-32h).

After decoding the read command, the decoded command is sent to thememory stack associated with the target memory die via the memory-sideinterface of the active I/O expander. In an embodiment, the read commandis transmitted to the selected memory stack of the target memory diewith the page address including the data to be read. In an embodiment,operation 430 can be performed for other commands associated with amemory stack, such as a read status command or a get feature command.The decoded read command is transmitted by a memory-side ONFI interfacevia an ONFI channel to the destination memory stack. In an example, theread command can be transmitted via the ONFI channel at a rate in arange of approximately 800 MT/s to approximately 1600 MT/s.

In operation 440, the processing device receives, via a memory-sideinterface of the active I/O expander, read data from the memory stackincluding the target memory die. In an embodiment, the read data (i.e.,the data read from the target memory die) is transmitted by the memorystack via an ONFI channel to the memory-side interface of the active I/Oexpander.

In operation 450, the processing device performs a signal conditioningoperation on the read data to generate conditioned read data. In anembodiment, the memory-side ONFI-compliant interface passes the readdata to a signal condition module of the active I/O expander (e.g.,signal conditioning module 240 of FIG. 2) to perform the one or moresignal conditioning operations. In an embodiment, the signalconditioning operation can include one or more of buffering and retimingthe read data. In an embodiment, the buffering operation can include oneor more I/O drivers configured to boost and reshape the slope of thesignal as it leaves the active I/O expander. In an embodiment, thedrive-strength and ODT settings help match this to the receiver. In anembodiment, the retiming operation can clock, latch and drive the signalout, helping clean up incoming jitter and further boosting performance.In an embodiment, the read data can be conditioned to satisfy applicablesignal integrity (SI) and performance requirements (e.g., exit latencyrequirements, reliability requirements, etc.)

In operation 460, the processing device sends, via the host-sideinterface of the active I/O expander, the conditioned read data to thehost system. In an embodiment, the processing device transmits theconditioned read out to the controller of the host system via thehost-side ONFI-compliant interface of the active I/O expander and theconditioned read data is sent via an ONFI-compliant channel at a datarate in a range of approximately 800 MT/s and approximately 1600 MT/s.In an example, the average data read of the conditioned read data sentto the host system is approximately 1200 MT/s.

FIG. 5 is a flow diagram of an example method 500 for an ONFI-compliantactive I/O expander of a memory-subsystem to manage a write commandprovided by a host system in accordance with some embodiments of thepresent disclosure. The method 500 can be performed by processing logicthat can include hardware (e.g., processing device, circuitry, dedicatedlogic, programmable logic, microcode, hardware of a device, integratedcircuit, etc.), software (e.g., instructions run or executed on aprocessing device), or a combination thereof. In some embodiments, themethod 500 is performed by the ONFI-compliant active I/O expander 113 ofFIG. 1. Although shown in a particular sequence or order, unlessotherwise specified, the order of the processes can be modified. Thus,the illustrated embodiments should be understood only as examples, andthe illustrated processes can be performed in a different order, andsome processes can be performed in parallel. Additionally, one or moreprocesses can be omitted in various embodiments. Thus, not all processesare required in every embodiment. Other process flows are possible.

At operation 510, the processing device receives, from a host system viaa host-side interface of an active I/O expander, a write command towrite data to a target memory die of a memory sub-system. In anembodiment, the write command is transmitted via an ONFI channelconnecting the host-side interface with a controller of the host system.In an example, the ONFI channel and host-side interface operate inaccordance with the ONFI protocol at a rate between 800 MT/s and 1600MT/s.

In operation 520, the processing device identifies a page addresscorresponding to the target memory die. In an embodiment, the active I/Oexpander determines which of the multiple connected memory stacksincludes the target memory die and identifies the corresponding pageaddress.

In operation 530, the processing device decodes the write command tosend to a memory stack associated with the page address corresponding tothe target memory die. In an embodiment, an ONFI command decode moduleof the active I/O expander (e.g., the ONFI Command Decode Module 250 ofFIG. 2) receives the write command from the host-side ONFI interface(e.g., host-side ONFI interface 260 of FIG. 2), inspects the writecommand, and decodes the write command. After decoding the writecommand, the decoded command is sent to the memory stack associated withthe target memory die via the memory-side ONFI-compliant interface ofthe active I/O expander. In an embodiment, the write command istransmitted to the selected memory stack of the target memory die withthe page address including the data to be programmed. The decoded writecommand is transmitted by a memory-side ONFI-compliant interface via anONFI channel to the destination memory stack. In an example, the writecommand can be transmitted via the ONFI channel at a rate in a range ofapproximately 800 MT/s to approximately 1600 MT/s.

In operation 540, the processing device receives, from the host systemvia the host-side interface of the active I/O expander, data to bewritten (also referred to as “write data”) to the target memory data. Inan embodiment, the host system can provide the write data to the activeI/O expander a short time duration following operation 530. In anembodiment, the write data (i.e., the data to be written to the targetmemory die) is transmitted by the controller of the host system via anONFI channel to the host-side interface of the active I/O expander.

In operation 550, the processing device performs a signal conditioningoperation on the write data to generate conditioned write data. In anembodiment, the memory-side interface passes the write data to a signalcondition module of the active I/O expander (e.g., signal conditioningmodule 240 of FIG. 2) to perform the one or more signal conditioningoperations. In an embodiment, the signal conditioning operation caninclude one or more of buffering and retiming the write data.

In operation 560, the processing device sends the conditioned write datato the target memory die. In an embodiment, the processing devicetransmits the conditioned write data out to the memory stack associatedwith the target memory die via the memory-side interface of the activeI/O expander and the conditioned write data is sent via anONFI-compliant channel at a data rate in a range of approximately 800MT/s and approximately 1600 MT/s. In an example, the average data readof the conditioned read data sent to the host system is approximately1200 MT/s.

In an embodiment, method 300 (of FIG. 3) can be performed as a part ofeither method 400 (of FIG. 4) or method 500 (of FIG. 5). In anembodiment, operations 310-330 can be performed for a read command inconnection with operations 410-460. For example, operation 410 can beperformed following execution of operations 320 or 330 (e.g., in theevent operations 320 and 330 are performed in parallel). In anembodiment, operations 310-330 can be performed for a write command inconnection with operations 510-560. For example, operation 510 can beperformed following execution of operations 320 or 330 (e.g., in theevent operations 320 and 330 are performed in parallel).

FIG. 6 illustrates a system having a 2×2 configuration whereONFI-compliant active I/O expander 613A is connected to memory stack680A and memory stack 680B, and ONFI-compliant active I/O expander 613Bis connected to memory stack 680C and memory stack 680D. Accordingly, inthe example shown in FIG. 6, if a target memory die (e.g., the subjectof a read command according to FIG. 4 or a write command according toFIG. 5) is part of the memory die set 681C, the processing deviceselects ONFI-compliant active I/O expander 613B B to process the commandand corresponding signals (e.g., as detailed above with respect tooperation 310 of FIG. 3).

FIG. 7 illustrates an example machine of a computer system 700 withinwhich a set of instructions, for causing the machine to perform any oneor more of the methodologies discussed herein, can be executed. In someembodiments, the computer system 700 can correspond to a host system(e.g., the host system 120 of FIG. 1) that includes, is coupled to, orutilizes a memory sub-system (e.g., the memory sub-system 110 of FIG. 1)or can be used to perform the operations of a controller (e.g., toexecute an operating system to perform operations corresponding to theONFI-compliant active I/O expander 113 of FIG. 1). In alternativeembodiments, the machine can be connected (e.g., networked) to othermachines in a LAN, an intranet, an extranet, and/or the Internet. Themachine can operate in the capacity of a server or a client machine inclient-server network environment, as a peer machine in a peer-to-peer(or distributed) network environment, or as a server or a client machinein a cloud computing infrastructure or environment.

The machine can be a personal computer (PC), a tablet PC, a set-top box(STB), a Personal Digital Assistant (PDA), a cellular telephone, a webappliance, a server, a network router, a switch or bridge, or anymachine capable of executing a set of instructions (sequential orotherwise) that specify actions to be taken by that machine. Further,while a single machine is illustrated, the term “machine” shall also betaken to include any collection of machines that individually or jointlyexecute a set (or multiple sets) of instructions to perform any one ormore of the methodologies discussed herein.

The example computer system 700 includes a processing device 702, a mainmemory 704 (e.g., read-only memory (ROM), flash memory, dynamic randomaccess memory (DRAM) such as synchronous DRAM (SDRAM) or Rambus DRAM(RDRAM), etc.), a static memory 706 (e.g., flash memory, static randomaccess memory (SRAM), etc.), and a data storage system 718, whichcommunicate with each other via a bus 730.

Processing device 702 represents one or more general-purpose processingdevices such as a microprocessor, a central processing unit, or thelike. More particularly, the processing device can be a complexinstruction set computing (CISC) microprocessor, reduced instruction setcomputing (RISC) microprocessor, very long instruction word (VLIW)microprocessor, or a processor implementing other instruction sets, orprocessors implementing a combination of instruction sets. Processingdevice 702 can also be one or more special-purpose processing devicessuch as an application specific integrated circuit (ASIC), a fieldprogrammable gate array (FPGA), a digital signal processor (DSP),network processor, or the like. The processing device 702 is configuredto execute instructions 726 for performing the operations and stepsdiscussed herein. The computer system 700 can further include a networkinterface device 708 to communicate over the network 720.

The data storage system 718 can include a machine-readable storagemedium 724 (also known as a computer-readable medium) on which is storedone or more sets of instructions 726 or software embodying any one ormore of the methodologies or functions described herein. Theinstructions 726 can also reside, completely or at least partially,within the main memory 704 and/or within the processing device 702during execution thereof by the computer system 700, the main memory 704and the processing device 702 also constituting machine-readable storagemedia. The machine-readable storage medium 724, data storage system 718,and/or main memory 704 can correspond to the memory sub-system 110 ofFIG. 1.

In one embodiment, the instructions 726 include instructions toimplement functionality corresponding to a cache management component(e.g., the ONFI-compliant active I/O expander 113 of FIG. 1). While themachine-readable storage medium 724 is shown in an example embodiment tobe a single medium, the term “machine-readable storage medium” should betaken to include a single medium or multiple media that store the one ormore sets of instructions. The term “machine-readable storage medium”shall also be taken to include any medium that is capable of storing orencoding a set of instructions for execution by the machine and thatcause the machine to perform any one or more of the methodologies of thepresent disclosure. The term “machine-readable storage medium” shallaccordingly be taken to include, but not be limited to, solid-statememories, optical media, and magnetic media.

Some portions of the preceding detailed descriptions have been presentedin terms of algorithms and symbolic representations of operations ondata bits within a computer memory. These algorithmic descriptions andrepresentations are the ways used by those skilled in the dataprocessing arts to most effectively convey the substance of their workto others skilled in the art. An algorithm is here, and generally,conceived to be a self-consistent sequence of operations leading to adesired result. The operations are those requiring physicalmanipulations of physical quantities. Usually, though not necessarily,these quantities take the form of electrical or magnetic signals capableof being stored, combined, compared, and otherwise manipulated. It hasproven convenient at times, principally for reasons of common usage, torefer to these signals as bits, values, elements, symbols, characters,terms, numbers, or the like.

It should be borne in mind, however, that all of these and similar termsare to be associated with the appropriate physical quantities and aremerely convenient labels applied to these quantities. The presentdisclosure can refer to the action and processes of a computer system,or similar electronic computing device, that manipulates and transformsdata represented as physical (electronic) quantities within the computersystem's registers and memories into other data similarly represented asphysical quantities within the computer system memories or registers orother such information storage systems.

The present disclosure also relates to an apparatus for performing theoperations herein. This apparatus can be specially constructed for theintended purposes, or it can include a general purpose computerselectively activated or reconfigured by a computer program stored inthe computer. Such a computer program can be stored in a computerreadable storage medium, such as, but not limited to, any type of diskincluding floppy disks, optical disks, CD-ROMs, and magnetic-opticaldisks, read-only memories (ROMs), random access memories (RAMs), EPROMs,EEPROMs, magnetic or optical cards, or any type of media suitable forstoring electronic instructions, each coupled to a computer system bus.

The algorithms and displays presented herein are not inherently relatedto any particular computer or other apparatus. Various general purposesystems can be used with programs in accordance with the teachingsherein, or it can prove convenient to construct a more specializedapparatus to perform the method. The structure for a variety of thesesystems will appear as set forth in the description below. In addition,the present disclosure is not described with reference to any particularprogramming language. It will be appreciated that a variety ofprogramming languages can be used to implement the teachings of thedisclosure as described herein.

The present disclosure can be provided as a computer program product, orsoftware, that can include a machine-readable medium having storedthereon instructions, which can be used to program a computer system (orother electronic devices) to perform a process according to the presentdisclosure. A machine-readable medium includes any mechanism for storinginformation in a form readable by a machine (e.g., a computer). In someembodiments, a machine-readable (e.g., computer-readable) mediumincludes a machine (e.g., a computer) readable storage medium such as aread only memory (“ROM”), random access memory (“RAM”), magnetic diskstorage media, optical storage media, flash memory components, etc.

In the foregoing specification, embodiments of the disclosure have beendescribed with reference to specific example embodiments thereof. Itwill be evident that various modifications can be made thereto withoutdeparting from the broader spirit and scope of embodiments of thedisclosure as set forth in the following claims. The specification anddrawings are, accordingly, to be regarded in an illustrative senserather than a restrictive sense.

What is claimed is:
 1. A method comprising: receiving, by a processingdevice from a host system via a host-side interface of an activeinput/output (I/O) expander, a read command to read a target memory dieof a memory sub-system; configuring a value setting associated with oneor more parameters of at least one of the host-side interface or amemory-side interface of the active I/O expander to enable Open NANDFlash Interface (ONFI)-compliant communications between the host systemand the target memory die; identifying a page address corresponding tothe target memory die; decoding the read command to send to a memorystack associated with the page address corresponding to the targetmemory die; receiving, via the memory-side interface of the active I/Oexpander, read data relating to the read command from the memory stackcomprising the target memory die; performing a signal conditioningoperation on the read data to generate conditioned read data; andsending via the host-side interface of the active I/O expander, anONFI-compliant communication comprising the conditioned read data to thehost system.
 2. The method of claim 1, further comprising selecting theactive I/O expander from a plurality of active I/O expanders in responseto the read command.
 3. The method of claim 1, wherein a set of signalstransmitted via at least one of the host-side interface or thememory-side interface are conditioned in accordance with one or moreONFI specifications.
 4. The method of claim 1, wherein the one or moreparameters comprise at least one of a drive strength parameter or anon-die termination parameter.
 5. The method of claim 1, furthercomprising initiating a calibration command to tune the value setting ofat least one of the host-side interface or the memory-side interface. 6.The method of claim 5, wherein the value setting are tuned to match aparasitic load on the active I/O expander.
 7. The method of claim 1,wherein the signal condition operation comprises at least one of abuffering operation or a retiming operation.
 8. A system comprising: amemory component; a processing device operatively coupled to the memorycomponent, the processing device to: receive, from a host system via ahost-side interface of an active I/O expander, a write commandidentifying a target memory die; configure a value setting associatedwith one or more parameters of at least one of the host-side interfaceor a memory-side interface of the active I/O expander to enable OpenNAND Flash Interface (ONFI)-compliant communications between the hostsystem and the target memory die; decode the write command to send tothe target memory die; receive, from the host system via the host-sideinterface of the active I/O expander, data to be written to the targetmemory die; perform a signal conditioning operation on the data to bewritten to generate conditioned write data; and send, via thememory-side interface of the active I/O expander, an ONFI-compliantcommunication comprising the conditioned write data to the target memorydie.
 9. The system of claim 8, wherein the processing device is furtherto select the active I/O expander from a plurality of active I/Oexpander in response to the write command.
 10. The system of claim 8,wherein the one or more parameters comprise at least one of a drivestrength parameter or an on-die termination parameter.
 11. The system ofclaim 10, wherein the processing device is further to initiate acalibration command to tune the value setting of at least one of thehost-side interface or the memory-side interface.
 12. The system ofclaim 11, wherein the processing device is further to match the valuesetting to a parasitic load on the active I/O expander.
 13. The systemof claim 10, wherein the signal condition operation comprises at leastone of a buffering operation or a retiming operation.
 14. Anon-transitory computer-readable medium storing instructions that, whenexecuted, cause a processing device to: receive from a host system via ahost-side interface of an active input/output (I/O) expander, a readcommand to read a target memory die of a memory sub-system; configure avalue setting associated with one or more parameters of at least one ofthe host-side interface or a memory-side interface of the active I/Oexpander to enable Open NAND Flash Interface (ONFI)-compliantcommunications between the host system and the target memory die; decodethe read command to send to a memory stack associated with the targetmemory die; receive, via the memory-side interface of the active I/Oexpander, read data from the memory stack comprising the target memorydie; perform a signal conditioning operation on the read data togenerate conditioned read data; and send via the host-side interface ofthe active I/O expander, an ONFI-compliant communication comprising theconditioned read data to the host system.
 15. The non-transitorycomputer-readable medium of claim 14, wherein the processing device isfurther to select the active I/O expander from a plurality of active I/Oexpanders in response to the read command.
 16. The non-transitorycomputer-readable medium of claim 14, wherein a set of signalstransmitted via at least one of the host-side interface or thememory-side interface are conditioned in accordance with one or moreONFI specifications.
 17. The non-transitory computer-readable medium ofclaim 14, wherein the one or more parameters comprise at least one of adrive strength parameter or an on-die termination parameter.
 18. Thenon-transitory computer-readable medium of claim 17, wherein theprocessing device is further to initiate a calibration command to tunethe value setting of at least one of the host-side interface or thememory-side interface.
 19. The non-transitory computer-readable mediumof claim 18, wherein the value setting is tuned to match a parasiticload on the active I/O expander.
 20. The non-transitorycomputer-readable medium of claim 14, wherein the signal conditionoperation comprises at least one of a buffering operation or a retimingoperation.